
/**
 * 栈的应用（括号匹配校验）
 *
 * @author Kevin
 * @date 2018-11-20
 */
public class Solution {

    public boolean isValid(String s) {
        ArrayStack<Character> stack = new ArrayStack<>();
        for (int i = 0; i < s.length(); i++) {
            char c = s.charAt(i);
            if (c == '(' || c == '[' || c == '{') {
                stack.push(c);
            } else {
                if (stack.isEmpty()) {
                    return false;
                }

                char topChar = stack.pop();
                if (c == ')' && topChar != '(') {
                    return false;
                }

                if (c == ']' && topChar != '[') {
                    return false;
                }

                if (c == '}' && topChar != '{') {
                    return false;
                }
            }
        }

        return stack.isEmpty();
    }

    public static void main(String[] args) {
        System.out.println(new Solution().isValid("(){}[]"));
        System.out.println(new Solution().isValid("(){[]"));
    }

}
